This study aims to develop a regression model using data from the Ammunition Stockpile Reliability Program (ASRP) to predict the shelf life of 81mm mortar high-explosive shells. Ammunition is a single-use item that is discarded after use, and its quality is managed through sampling inspections. In particular, shelf life is closely related to the performance of the propellant. This research seeks to predict the shelf life of ammunition using a regression model. The experiment was conducted using 107 ASRP data points. The dependent variable was 'Storage Period', while the independent variables were 'Mean Ammunition Velocity,' 'Standard Deviation of Mean Ammunition Velocity,' and 'Stabilizer'. The explanatory power of the regression model was an R-squared value of 0.662. The results indicated that it takes approximately 55 years for the storage grade to change from A to C and about 62 years to change from C to D. The proposed model enhances the reliability of ammunition management, prevents unnecessary disposal, and contributes to the efficient use of defense resources. However, the model's explanatory power is somewhat limited due to the small dataset. Future research is expected to improve the model with additional data collection. Expanding the research to other types of ammunition may further aid in improving the military's ammunition management system.

This study reports Chinese and Korean university EFL students’ perceptions of and attitudes toward online and face-to-face English language learning modes during COVID-19. Few previous studies have focused on how students thought of online and face-to-face learning experiences of subjects regarding new concept learning and delivery of new contents. Research gravitating around English courses showed students' mixed perceptions. The survey was conducted for 302 Korean and 337 Chinese university students who took communication-oriented English courses. Descriptive statistics and qualitative data analysis were used for analysis. Results indicated that students preferred face-to-face English learning with some specific indications of achieving a stronger help and quality for communicative competence in language. Online learning also benefited students with a sense of both flexibility and independence. Positive components of face-to-face learning for language education might be considered for online education while incorporation features such as flexibility and independence to enrich language education during COVID-19.

The world Englishes framework gravitating around many recent models of English has initiated sharp interest in adopting intercultural awareness and its teaching/learning in English language instruction. This is because English has become ‘a heterogeneous language with multiple norms and grammars’ (Canagarajah, 2006) and no longer an international language but an ‘intercultural language’ (Sifakis, 2004). Intercultural English language teaching (IcELT) aims to create interculturally multidialectical English users among world Englishes by not only developing cultural tolerance and linguistic and cultural diversity but abating the so-called native-speakers’ linguistic and cultural dominances. For this, this article suggests eight workable IcELT guidelines which could facilitate users’ IcELT competence. This article, for its organization, first addresses why IcELT in relation to the world Englishes framework should be dealt in the contemporary ELT arena. Secondly, it suggests the eight IcELT guidelines along with some classroom techniques; thus, teachers of English language will benefit in his/her future lesson plans.

The 16 priority PAHs (Polycyclic Aromatic Hydrocarbons) designated by US Environmental Protection Agency were analyzed for some digested sludges from wastewater treatment plants in Korea. PAHs are an important group of organic contaminants present in sewage sludge due to their persistence and toxic potential. PAHs were extracted from freeze-dried sludges using a methylene chloride-methanol (2:1) mixture in a soxhlet extractor. The extracts were cleaned-up by silica gel/alumina combination column and subsequently fed into gas chromatograph/mass spectrometer (GC/MS) for determining PAH contents. The sum of the 16 PAHs in the sewage sludge varied from 534.8 to 5754.5 ㎍/kg, dry wt.. In the sewage sludge, phenanthrene appears as the most abundant PAHs, followed by naphthalene, pyrene, fluoranthene. Source of the investigated sewage sludges relatively predominated pyrogenic. PAHs levels of sewage sludges in Korea appeared to be lower than those in other countries.